Riveting machine



Jan. 29, 1946. N, NE, SWANSON 2,393,720

RIVETING MACHINE Filed Feb. l1, 1944 5 Sheets-Sheet l /NVENTo/Q N/s 5:5 WA NSO N.

F/G 4 Hfs ATTORNEY.'

Jan. 279, 1946. N, E, SWANSQN 2,393,720

RIVETING MACHINE Filed Feb. 11(4 1944 3 sheetslsheet 2 H/ A TTORNEY Jan. 29, 1946. N. E. swANsoN RIVETING MACHINE Filed Feb. l1. 1944 3 Sheets-Sheet 5 F/G, /O

Patented Jan. 29, 1946 RIVETING MACHINE Nils E. Swanson. New York, N. Y., assignor to General Motors Corporation, Detroit, Mic a corporation of Delaware Application February 1l, 1944, Serial No. 521,937

(Cl. 21,9-2)l Claims.

This invention relates to riveting machines and comprises all of the features of novelty herein disclosed. An object of the invention is to provide an improved machine for riveting or upsetting the ends oi bars, studs or the like to secure them. to another part. Another object is to provide an improved machine adapted for riveting one` end at a time or simultaneously riveting the opposite ends of a bar, stud or the,` like to unit a pair of parts. Another object is to provide a machine for equalized riveting or upsetting of the oppositeends of the tie bars of a. bearing cage or Ithe like to secure the tie bars to the end rings of the cage.

To these ends and also to improve generally upon devices of this character, theV invention consists in the various hereinafter described and claimed'. In its broader aspects, the invention is not necessarily limited to the speciiic cony struction selected for illustrative purposes in the accompanying drawings in which Fig. 1 is a side elevation of themachine, some parts being in section.

Fig. 2 is a top viewy of the floating work tablel in retracted position.

Fig. 3 is a top view of a portion of a supporting bracket and guide.

Fig. lis a frontview ofthe table.

Fig. 5 is a side View of the table in retracted position.

Fig. 6 is a front View of the upper portion of the machine, some parts being broken away and in section.

Fig. 7' is a plan view of electrodes and associated parts arranged for single end riveting.

Fig. 8 is an exploded view of parts of a roller bearing cage.

Fig. 9 is a plan view of the upper portion of the machine, some parts being omitted.

Fig. 110 is partly a vertical sectional View and partly a side elevation.

The machine is particularly designed for riveting the tie bars of cages for roller bearings. As shown in Fig, 8, one well known form of roller bearing cage comprises a pair of opposite end rings E to be connected by tie bars T which have reduced' studs or projections P at eachend to be upset on the outer walls of the end rings or into countersunk openings C therein, the shoulders S at the base of the projections abutting against the inner walls of the end. rings to space the latter. The bearing rollers R may be hollow to sleeve over the tie bars prior to riveting or they may be otherwise retained between adjacent tie-bars. The rollers may beV of the spirally Wound type if desiredr as indicated in Fig. 1 wherein a narrow cage is shown in riveting position. In any case, the assembled cage parts are clamped together by some suitable holder for the riveting operation.

In Fig. l, a table supporting bracket or knee 2 is adjustably secured to a main frame 4 by clamping bolts. The selected level depends on the axial width of the bearing. Projecting forwardly from the bracket is a Vertical web 8 supporting two vertical rows of flanged rollers I0 which are rotatable on bolts I2. vertically guided by lowerend engages a roller I6 on a lever I8 which is pivoted to the bracket at 20 and carries a counterweight 22 which is adjustable along the lever. The weight is just sufcient to slightly overbalance the Weight of all the parts supported on the roller I6 including the work and its holder, the upward movement being limited by a stop screw 24'.

The vertical bar or slide I4 is fastened by bolts at its upper end to a depending lug on a horizontal guide plate 26. On this guide plate a work supporting table 28V having rgibs 30 is guided from front to rear to carry the work to the riveting position. Thev table has intersecting undercut slots 3| in its upper face to receive T-headed bolts which clamp a series of kWork locating plates 32 in adjusted position.

These plates are shown widely separated but are adjusted in 'accordance with the diameter of the cage or the diameter of whatever holder is used toclamp the assembled parts of the cage. No holder is shown but it includes a peripherally scalloped member 34 sufliciently thick to keep the tie bar projections P clear of the top of the table. At the rear the table has a slot 36 which will accommodate or loosely receive a fixed lower electrode 38 when the table is moved rearwardly with the work. For single end riveting the table is supported by vertical stop plates 40 Welded to the top of the knee 2 at opposite sides of the electrode 38.

A suitable transformer has secondary termi- .nals- 42 one of which is fastened to a cap 44! which is grooved on the bottom to co-operate with a similarly grooved rest 46 mounted on the bracket 2 for the purpose of clamping a cylindrical horn 48. The front of the horn has a vertical groove co-operating with a similar groove ron a clamping cap 50 which is fastened by screwA bolts to the holder to grip the fixed lower electrodeA 38. The tip of the electrode 38 is thus held in an adjusted position just below the rollers is a bar or slide I4 whose the level of the projections P on the tie bars and in a line vertically with one of the projections when the table is moved with the work from the loading position of Fig. 5 to the riveting position of Fig. 1.

Directly above the xed electrode 38 is an upper axially movable electrode 54 secured by a cap 56 (Fig. l0) to the front of a holder 58 which is fastened to aV horizontal web B0 on a rearward projection from a front slide 62 which is guided vertically in ways on a rear slide 64 which is also guided vertically by gibs 65 on an overhanging portion of the frame. The front slide 62 is connected at its top to a piston rod 66 projecting downwardly from an air cylinder 88. A flexible band conductor 'l0 of generally U-shape and which may be laminated is connected to a secondary terminal of the transformer and to a ange 'l2 on the rear end of the holder 58 which supports the upper electrode 54. The front slide is centrally recessed at the bottom as indicated at 'I4 in Fig. 6 to clear the upper portion of the electrode 54.

When the bracket 2 and hence the table 28 have been adjusted to the proper height for the cage to be riveted, the assembled cage is supported and located by its holder upon the `table and the latter is moved rearwardly until one of the tie bars is in line with the two electrodes and between them. The air cylinder 68 then moves the slide 62 downwardly and forces Ithe upper electrode against the tie bar. The air cylinder and the heating current may be controlled by any suitable means which operates a solenoid valve and timing mechanism. The pressure on the tie bar is transmitted to the cage and to the iloating table 28 which descends until the lower end of the tie bar engages the lower xed electrode and completes the heating circuit whose `period is controlled by the timing mechanism. When the reduced ends of the tie bar are heated to the proper temperature, the riveting pressure upsets both ends at once. The pressure of the riveting operation is equalized upon the two ends of the tie bar by the floating table which will descend slightly as the pressure overcomes the weight 22. The projections P of course decrease in length as they are upset. Upon release of the pressure, the table rises and the cage is manually indexed around to bring the other tie bars one by one to operative position for riveting.

When the machine is thus used to rivet both ends of a. tie bar simultaneously, the reduced ends of the tie bars are heated by resistance with the heating current passing from one electrode through the tie bar lengthwise to the other electrode. The machine also has instrumentalities for use in riveting a tie bar or other object at one end only. In this case the lower electrode is removed and a pair of hold-down electrodes are brought down on the upper end ring at each side of the tie bar so that heating current passes from the upper electrode into the upper end of the tie bar and horizontally through the end ring to the hold down electrodes at each side.

An air cylinder 80 which is smaller than the cylinder 58 has its piston rod 82 pivotally connected `to a lever 84 hung on a link 86 which is pivoted at 88 to a bracket on the frame, the front end of the lever being pivoted to the rear slide 64.

'he rear slide has lower lugs 90 and upper lugs S2 in which vertical rods 94 are slidably and yieldably mounted, a coil spring 96 being interposed between each lug 92 and nuts 98 ythreaded on the rod. An adjustable stop collar 99 is threaded on each rod above the lug 90. The lower end of each rod is secured to a, cap |00 fastened to a block |02 which is provided at the bottom with a T-slot for a. T-headed bolt |04 by which a water cooled holder |06 is clamped in adjusted position laterally and angularly. Short additional guide rods |01 secured to the cap |00 lproject; upwardly into holes in slide 64. On each holder |06 is a hold-down electrode |08 adapted to engage the upper end ring E of the cage alongside of a, tie bar. The adjustment provided by the T-bolts enables .the electrodes to engage the desired areas on end rings for cages of different diameter or wherein the spacing of the tie bars of different cages varies. Each block |02 is connected by a U-shaped flexible band conductor ||0 to one of the secondary terminals of the transformer.

For single end riveting, the counterweight 22 is moved to the left to make it ineffective and the table is thus lowered onto a solid support provided by the stop plates 40 so that the table does not float. If the article to be riveted is a tie bar for a roller cage, the cage is clamped in a fixture and located on the table with one tie bar under the upper electrode 54. The air cylinder causes the hold down or side electrodes |08 to descend yieldably on the upper end ring before the larger air cylinder 68 brings the upper or central electrode down onto the tie bar to complete the heating circuit. When the end of the tie bar becomes sufficiently hot, the upper electrode applies a pressure to cause upsetting. The upper or center electrode then rises followed by the side electrodes which release the work.

I claim:

1. In a machine for riveting the opposite reduced ends of a shouldered tie bar to connect a. pair of parts, a pair of opposed riveting members, means for causing a relative movement of approach between the riveting members to cause them to directly engage and upset the opposite ends of the bar, a yieldable table for supporting the pair of parts with the bar t0 be riveted between the members, and means for counterbalancing the weight of the table and the parts supported thereon to insure equalized riveting pressure upon the opposite ends of the bar.

2. In a machine for riveting the opposite reduced ends of a shouldered tie bar to connect a pair of parts, a pair of opposed riveting members, means for causing a relative movement of approach between the riveting members to upset the opposite ends of the bar, a work supporting table mounted to move in the direction of said approach, and a counterbalancing device for neutralizing the weight of the table and the parts supported thereon to prevent said weight from creating greater riveting pressure on the lower end of the bar.

3. In a machine for riveting the opposite ends of a bar to connect a pair of parts, a pair of opposed riveting members, means for causing a. relative movement of approach between the riveting members to upset the opposite ends of the bar, a slide movable in the direction of said approach, a work supporting table movable crosswise of the slide at a level to carry the work freely between the riveting members, and means reacting on the slide for urging the table towards said level.

4. In a machine for riveting the opposite ends of a shouldered tie bar to connect a pair of parts, a lower electrode fixed in position, an upper electrode movable towards the lower electrode to upset the opposite ends of the bar, a work supporting table for supporting the pair of parts with the bar passing through them in line with the electrodes, and means for yieldably supporting the table to hold the bar clear of the lower electrode until the upper electrode is moved to upsetting position.

5. In a. machine for riveting the opposite ends oi' a bar to connect a pair of parts, a lower electrode xed in position, an upper electrode movable towards the lower electrode to upset the opposite ends of the bar, a work supporting table movable crosswise of the electrodes at a level to carry the work freely between the electrodes. the table having a notch to receive the lower electrode, and means for yieldably supporting the table.A

NILS E. SWANSON. 

